module basic_multiplier_cell (Pin, plusj, minusj, mi, Cin, Pout, Cout, signext_external);
	// Input and output
	input Pin, plusj, minusj, mi, Cin;
	output Pout, Cout, signext_external;
	
	// Wires
	wire signext;
	
	// implementation
	assign signext = (mi & plusj) | (~mi & minusj); 
	assign signext_external = signext;
	
	full_adder(signext, Pin, Cin, Cout, Pout);
endmodule
 